Twisted strap conveyer



April I F. C-ROZIER 1,997,360

TWISTED STRAP CONVEYER Original Filed. Jan; 18, 1935 INVENTOR F. CROZIER Man-3W ATT RNEY Patented Apr. 9, 1935 v t h I v V J e-umw T T TENT" QFFICE TWISTED swa oo vEYEn- ,Franklyn Crozier, Woodhaven, N. I assignor to l The Western Union Telegraph Company, New 1 York, N. Y., a corporation of New York i lteiiid for abandoned application, Serial No. H

652,375, January 18, 1933. This application MarchZ, 1935, Serial No, 9,125 l l i a p H Claims; (oi. ma-165 p This case is a substitute forabandoned applicabelt folded to provide two straps along the active tion Serial No. 652,375. r. j l run of the coveyer; and, l This invention relates to belt conveyers and -Fig.-2 is a diagrammatic view'illustrating a more particularly to the conveyers in which ma-., multiple strap conveyer employinga single belt 5 terial is carried between two fiat. belts asit is folded to providethree straps arranged tocon- 15 transported along the conveyer. vey material in both directions of travel. 7

It has-beerr proposed heretofore to twist the ThearrangementillustratedinFig. 1 comprises A two contacting belts or straps of the above type an endless conveyer belt l0, driven by a motor of conveyer so that the material ismore firmly l I or other suitablegdriving means, through a 10 gripped between the adjacent surfaces of the drive pulley l2. The'belt extends from the drive ll) belts. .The double ormultiple strap conveyer has pulley preferably arounda take-up idler pulley been found to be admirably adapted to carry cerl3 and a secondary idler pulley M which brings tain types of light'fiexible sheet material such as the belt back in proper alignment The'ditickets, coupons, message blanks and the like when rections in which the conveyer. unit employing a arranged with the contacting strapstwisted toe single belt may beextended are notlimited. In 15 gather alongthe conveyer-run. the illustration "the active route of the-conveyer The principal object ofthis invention is to proextends upwardly. from a pair of idler pulleys l5 videa twistedstrap conveyer arrangement which and it to a directionchanging pulley. l1, thence will enable a single endless conveyer belt toserve along a horizontal direction to another direction 1 to provide both of theconveying straps, strap changing pulley I8, thence downwardly to dis- 20 folds, or strands so that the entire belt system charge the material ata pairlof return pulleys of the conveyer may bet driven by applying a 2land22l ,1 i 1 driving force, through a suitable 'pulley'at onel As the sheets travel along the twisted strap point. i i portion of the conveyertheyrevolve ina spiral Another object of this invention isto adapt the andmay" become partially wrapped; around the 25 same system to a conveyer embodying more than strapsidue .to the resistance of the air in traveL- two folds ofasingle strap arranged to provide two If V desired a pair of pulleys 26 and Z'lmay be or more conveyer paths. along the same route. disposed abovethe outlet or discharge end of the When double strap conveyersarepassed around conveyer route for straightening outthe twisted 30 pulleys for changing theirdirection-of traveLlthe portion of the conveyer beforethe two folds of 30 strap farthest from the face of the pulley due to the belt or strap reach the discharge pulleys 2i the largeriefiectivediameter or radius of travel and 22; Thepurpose of this isto give thesheets will tendto creepahead oflthe strap nearest the time to straighten themselveswith the edges of face ofthe pulley. Where there are several the belt before they pass between the final pul- 5 changes of directioninthedouble strap portion of leys. V w w V l the conveyer, this creeping tendency becomes Thetravel of the .belt through the system .of quite pronounced having, at times, a: distinct pulleys from the drive pulley :12 around both detrimental effect on the conveying action of the sides of the conveyer route will now be traced straps. 1 In otherwords, when one strap tends to to'show'how the single endless conveyer belt is i 40 continuously creep over, the other, the grip of arranged or folded to provide the belts orstraps 40 th st ap su ia sup t material being conat both sides of the conveying path and also veyed maybe materially weakenedfi'and in some how the tendency for the belts to creep in passas v n permit thematerial to fall out of the ing the direction changing pulleys is substanconveyer- V i J "'T 1. i l tially overcome. For convenience, the portion or Another object of this invention is, therefore, fold of the belt passing along thelower return 45 to cut down asfar as possible, and even substanpath and entering the inlet at the right .will be tially eliminate the tendency of one belt 'or strap designated as a, while the other fold passing to creep over another when they are both passing along he upp re n 11m and entering the around the same direction changing pulley. i let fromvthe left will be designated as b. The "These and otherobjects will be apparent from am d a -W l be followed through t V the following description and claims taken totwisted D h conveyer until the f d gether with theaccompanying drawingforming a Joins t b 'a Viceversai 7 part of thisapplication in which; Y The a fold of the belt'or strap may be read- Fig. l is ;a diagrammaticview illustrating a ly followed from the exit or discharge pulley ouble straptwisted conveyer employing a single 21 tothe entrance pulley l'5. From this point 5 ferenoe in the. effective acted by a. similar tendency at adjacent pulleys the a fold passes from tion over to the right side, while the b fold passes the. idle path, it will be seen or merge into the folds passes. in at the entrance on position and out upper position.

- number-of. half turns, asbelt fold a,

at the discharge around the pulley Z2 upward "end around the pulley 2| tendto eliminate the creeping. Another item to be noted is the entrance and the 5? while the 1) side of the twist between first direction changing pulley fold passes around the rear side of the twist.

At the pulley ii the 1) fold comes against the face of the pulley while thea fold is at the outside. Continuing along the second half turn the a fold comes to the front and the 1) fold is behind. Through the third half turn the i) told comes to the irontv again with a fold behind where they arrive at the second direction changing pulley it. They pass around this pulley with the a told on the inside next to the face of the pulley and the "1) told on the outside.

From the second direction changing pulley H3 the straps extend with another half turn to 26 and 21'. At the same time,

the inside or left posithe guide pulleys underneath to the left side. Since there is no twist: between. guide pulleys 2% and 2?, the folds passout at the end of the conveying path with the a iiold at 'theright passing around the discharge pulley 22 and the 1) fold at the left passing around the discharge pulley 2i. Tracingthese belt sections or folds back along that they become opposite that first asthe a fold of the belt the inside or lower at the outlet on the outsideor Following a particular point it moves around this path or the drive pulley l2 around 'sumed; 'In other words,

along the belt as course of travel from entrance pulley 15', it passes through the twist has an odd thence out of the belt, which it will be noted around theputside pulleys 24 and. 25 back to the entrance and around the pulley it, through the: twisted section as belt fold I), along the odd number of half turns to the outlet or discharge thence to the starting point at the pulley l2. d 1

From the foregoing description several features and advantages will. be noted. The first of these is that an. odd number of. half turns is required to enable. the reversal of the idle or return folds "of the belt to make the complete circuit of travel. Any number of twists or half turns may 'be made in the to p'roduce the well known additional gripping action of a twisted belt or strap conveyer. As it is known thenurnber of twists are limited somewhat by the rigidity of the straps and the dimensions er thickness and width. The second item is that a single belt forms both sides of the double strap conveyer so that they may be driven at one point thus assuring that the same tension and speed will be exerted on both of; the. sides of the twisted portion, which will that when an odd number oihalf turns are. employedin each of the various sections extending between direction; changing pulleys the belt fold which is travcling against the face of the pulley at one direction changing point, will be traveling inthe outer position at the other direction changing point." This means-that the tendency to creep at anyone ofthe several pulleys due tothe'diftravel radii is counteracting onthe folds in reverseorder so that in the beltv as awhole there is no. resulting cumulagle endless belt ceiving power from asuitable belt which. is desirable 'themiddle pulley 35.

the tendency for one of the 'folds to creep along thickness. 'lt has been foundthat certain types of belting provide all of the necessary properties otherwise desirable with only a small portion of the thickness ordinarily thought necessary. Certain types of fabric or webb belting are found to havethese properties.

reduce travel radii differential and to that extent reduces quantitatively the. creeping tendency at direction changing pulleys.

. Fig. 2 illustrates another embodiment of this invention. It shows an arrangement of a sinpaths along a single route. It also illustrates how the belt may be arranged or folded to provide conveyer paths in both directions of travel of the belt. A single conveyer belt 3'! movesior travels three times through the conveyer route,

each, time assuming a different one of three positions along the route to providetwo double strap conveyer paths therealong. For conveniencethe turns of the belt-entering the inletend of the conveyer in a certain position will be designated the same throughout both the forward. and

The entrant end of the conveyer the left end where the belt assemdrive pulley 32 rereturn routes. is provided at bly is driven ,bymeans of a source. The belt fold at the lower; or, extreme outer side of the drive pulley 32 will be designated belt .r. The fold in the middle portion on pulley 32 will be designated belt 11; while the fold next to thepulley will be designated belt a. It will be noted that the entrance betweenbelts or folds and z is at a pulley 34. elevated above the pulley 32. .The forward-or lower route of the conveyer extends from pulley 32 upwardly around a direction changing pulley35, thence in to another direction a horizontalv .direction changing pulley3ii, thence downwardly to the exits between. the various belt pairsformed at pulleys 31,38. and 39.

The belt folds will now be half turns from pulley 32"to the exit pulleys ifl', 38 and 39.. Between the pulleys 32 and 35 the fold a: passes from an extreme outer right position to an extreme outer'left position at the pul-. ley 35.4 The fold y will assumea middle posi- How- I tion throughout the entire forward route. ever, the fold 2 moves from an extreme left inward position at pu1ley32 to an extreme right inward position at the pulley 35. that the assembly makes only one-half turn between pulleys 32 and 35. Between pulleys 35 and 38 the assembly makes two half'turns, the fold x moving over around the back through the first half turn and over around the front through the second half turn to assume anextreme outer;

position at the pulley 38. Likewise the fold z movesirom an inner position over'the iront through the second half turn to an inner position around the pulley 36. Between the pulleys 33,731, 38 and 3a the turn, the fold a: moving to an extreme outer position and passing around the lower; pulley 39. The fold yin the middle position passes around i The fold 2 passes from the inner position at pulley 36 around over the The particular advantage to be gained'is that thin belts,

providing a plurality of conveyer motor .33 or other traced through their It will be noted assembly makes one-half *front to the Lfold zl at 31. i! and a are separated from each other to form the l discharge spaced apart.

lrection changing ferred to.

andy as theyfpass a pulley 42.

pulley 31 and is separated'from the 1 It will be noticed thatthe folds w,

by the pulleysn3'l, 38 and 39 being This point constitutes the end of the first conveyer path. 1 e L It will be notedthatthe belt assembly -is' passedthrough an evennumber of half. turns'in ythe'first portion of the conveyer route! Even 10.

At a point adjacent theoutletor discharge .end

of the first conveyer route the entrant end ofthe second conveyer route is located. The: inlet bee tweenfolds a and 'y' is providedby permitting them to come together around a pulley 4! while the inlet between the foldsy. and a is provided a to contact the; folds m From the inlet of the second route the belt assembly passesupwardly around a direction changing pulley 43 thence along the horizontal runto a vdirection changing pulley 44 and downwardly around pul-' by arranging the fold ,leys 45, 46 and 41 providing exitsor discharges around the pulley 46 at which for the paths of the second route. Tracing the belt portions or folds the fold apasses over the frontthrough a half turn between pulleys 42 and 43 to assume an inner position at the face of the pulley 43. The 1 fold is still in the in.- termediate position throughout the second con-f veyer route. The a fold moves from an inner position around the back of the first half. turn to the outer position at the pulley '43. From the pulley 43 the assembly is passed through three half turns. The fold ac passes around theback of the first half turn, around the'front of the second half turn, around the back of the third half turn to assume an outer position at the pulley 44. The folda passes around the "front of thefirst half turn, around the back of the second half turn and around the front of the third half turn to assume an inner position atthe pulley 44. From this point the assembly passes to the discharge pulleys through a single half turn. The fold a passesaround the front of 'the half turn to be separated from the contral fold y at the pulley 45. The fold :11 passes point it isseparated from the a fold which is passed around the back of the half turn to the pulley 41.

Itwill now be noted thatthe various belt folds continue over the inlet pulleys 32 and 34 respectively. It will'be particularly noted, however, that the various belt folds in passing over the latter pulleys become a fold other than that first assumed. For instance, the fold a: which passes around pulleys 45 and 34meets the fold y at the i pulley 34 and makes a half turn around the back between ,pulleys34 and32 to assume a middle position at the pulley 32 and joinswith what was assumed originally occupied a mid-position, in making the half turnbetween pulleys 34 and 32 withthe fold in, assumesan inner or left position and joins with what was originally assumed to be belt fold 2. Finally, fold 2 passes around the outside of pulleys 41 and 32 and joins If the travel of continuous belt 3! odd number of half changing pulleys by employing the number as the total pair or" adjacent belts faces in contact to form a'conveyer path along with what wasio'riginallyassumed to be fold any particular point of the is followed three times through return routes i of the conveyer the L forward and it "will beseen that it will finally arrive at the v same position from which it originally started.

Thus it is demonstrated thataesingle' belt can bearranged' to form a plurality of-conveyer paths g along both forwardjand return-routes of a twisted doublestrap conveyer? This arrangement pro-. vides all of the several, advantages pointed out in connection with the embodiment of Figs-l,

a tendency to out down creeping by employing an turns between direction t has been found also that if thetypeof conveyeribeit: described in connection withthe foregoing embodiment is employed the effective 'dilfere'nce inthe" travel radii about the direction changing pulleys will be minimized, which in turn further "minimises the tendency for creeping of the other. In addition to the advantages pointed out in connection W'ithithe foregoing embodiment this embodiment demonstrates how a single end- Y less belt may be arranged to form active conveyer paths alongboth the forwa1-d-and' return directions of travel of the belt. 3

Although the embodiment of l 'ig. lwas described as providing only one conveyerroute it may be arranged to provide an additional conveyer route along the return travelor the belt principles illustrated in the embodiment of Fig. 2. It will further be noted that although only one half turn of the conveying sections of the belts or straps is provided in the vertically extending sections any suitable odd number of turns maybe employed.

Although it has been pointed out that odd numbers of turns in the belt arrangement have been employed it should be particularly noted that such number of turns arenot to be arranged in the-order illustrated so long as the essential arrangement of having an odd number of halfturns included in the entire perimeter of the route or path of travel of the belt.

belts onewith relation to the ie V such asa single drive for the whole beltsy'stem,

necessarily From the above description it will be seen that a conveyer arrangement hasbeen provided which.

enables. a single belt to form the straps at both;

sides of the conveyer path in a double strapqtype of conveyer, particularly of the twisted belt type;

Further, a single belt may be arranged to form i not only a single double strap path but aplurality 'of paths. Such number of paths may be extended: to any desired suitable number. It should further be noted that an arrangement has been provided which substantially eliminates the tenduency for'the belts to creep one with respect to the other as they pass around the direction changing pulleys-in this type of arrangement.

Whilethis invention hasbeendesoribed in but two forms, it will be obvious to those skilled in I the art that it is not so limited, but is susceptible to various other changes and modifications without departing from the spirit thereof, and it is desired; therefore, that only such limitations shall be placed pended claims. i

What I claim is: L l. Ina fiat belt conveyer, conveying means disposed along a conveyer route embodying a twisted together with their thereon as are imposed by the prior art or as specifically set forth inthe ap- 1 face or" the pulley, whereby thecreeping tendencies at adjacent pulleys are opposed to each other.

changingpulleys along said belts and around which said route, direction route common to both said belts pass, one belt in an outer position and the other in an inner position, whereby the inner belt .travels at a certain eifective diameter and the outer belt travels at a relatively larger effec tive diameter, producing a tendency for one belt to creep with respect to the other, the portion of between "adjacent direction twisted for reversing the belts with respect to the said belts disposed changing pulleys being relativeposition of the 2. In a belt conveyer in which a plurality of conveying paths are formed, along a conveyer route by means of. the adjacent contacting surfaces of oppositelydisposed belt sections being positioned 'to travel in contact with each other,

' a single belt providing an arrangernent for forming several paths, said arrangement being characterized by the'fact that the number of half turns in the belt section along the forward route together with those inthe sections along the return route equal an odd number and by the fact that all of the belt sections save one are twisted anodd number of half turns between the point Where the forward and return sections merge into each other.

. 3. In flat belt conveyer, conveying means disposed along a route and embodying a pair of adjacent belts twisted together with their faces in contact to form a conveyor path along said route,

guide pulleys around which the belts travel, one

" cent belt in anouter and the other in an inner posialong said route where changes of direction occur, said pulleys, being common to both belts, whereby the different effective diameters at which the belts travel tend to produce a creep of one belt with respect tothe other, said belts being of minimum thickness, whereby said tion, at points creeping tendency is reduced to a minimum, the.

. pulley.

4. Abelt conveyer comprising'alsingle belt and guide pulleys arrangedto suppo-rt the belt, said belt' embodying a plurality of folds disposed to travel in contact with each other, said folds being ,soarranged ina series of half turns that different folds engage adjacent guide pulleys; l

-5. Abelt conveyor comprising a single belt and guide pulleys arranged it changes its direction of travel, said belt embodying a plurality of folds disposed to travel in' contact'with each other, said folds being so arranged in a series of half r turns that opposite tosupport the belt wherev folds engage adjacent guide pulleys," whereby the J normal tendency for belt creepage at the change i of direction pulleys is counteracted.

, RANKLYNCROZIER. 

